Referencing a DbDataSource

I am writing a plugin for a PHP framework that simplifies work with the database.

When the user is viewing the database configuration file, I'd like them to be able to Ctrl+Click on a database name within a PHP string literal and be taken to the schema in the Database Tools window. Is this possible?

I tried the following. However, dataSource.getReference() always returns null.

public class DatabaseGroupReferenceContributor extends PsiReferenceContributor {
    @Override
    public void registerReferenceProviders(@NotNull PsiReferenceRegistrar psiReferenceRegistrar) {
        final PsiElementPattern.Capture<PsiElement> pattern = psiElement()
                .inVirtualFile(virtualFile().withName(string().matches("database.php")));
        psiReferenceRegistrar.registerReferenceProvider(
                pattern,
                new PsiReferenceProvider() {
                    @NotNull
                    @Override
                    public PsiReference[] getReferencesByElement(
                            @NotNull PsiElement psiElement,
                            @NotNull ProcessingContext processingContext) {
                        if (psiElement instanceof StringLiteralExpression) {
                            String nameInCode = ((StringLiteralExpression) psiElement).getContents();
                            MyDatabaseService service = ServiceManager.getService(psiElement.getProject(), MyDatabaseService.class);
                            for (DbDataSource dataSource : service.getDataSources()) {
                                JBIterable<? extends DasNamespace> schemas = DasUtil.getSchemas(dataSource);
                                for (DasNamespace schema : schemas) {
                                    String name = schema.getName();
                                    if (name.equals(nameInCode)) {
                                        return new PsiReference[]{
                                                dataSource.getReference()
                                        };
                                    }
                                }
                            }
                        }
                        return new PsiReference[0];
                    }
                }
        );
    }
}